1. To over react over something
2. To be out of your mind
3. To do everything and anyone for your girl/boy, almost doing more than you should, making sure you're doing everything you can to ensure they will stay with you etc. sprung

Sierra was leaving 10 messages on Daniel's phone at one time, sending him e-mail after e-mail, linking his cell 24/7... etc. she was trippin over him.